Method of Predicting Acoustic Performance of Porous Polymer Material and Program to Perform Same

This application claims under 35 U.S.C. § 119(a) the benefit of Korean Patent Application No. 10-2024-0056492, filed on Apr. 29, 2024, the entire contents of which are incorporated herein by reference.

The present disclosure relates to a method of predicting acoustic performance of a porous polymer material and a program to perform the same, in order to predict the acoustic performance of the polymer material that typically is deteriorated by time and temperature.

The Layton model and the Arrhenius model are known as models for predicting changes in properties of polymer materials that deteriorate with time and temperature.

In addition, research is ongoing on models that predict mechanical properties such as tensile strength, impact strength, modulus, etc., and non-acoustic properties such as porosity, airflow resistivity, etc. of deteriorated polymer materials, but no method has been proposed to predict the acoustic performance, for example, sound absorption coefficient and sound transmission loss, of deteriorated polymer materials.

In addition, most properties of conventional models for predicting the mechanical and non-acoustic properties of deteriorated polymer materials are represented as integers, so calculations are simple and the deviation is small even when test values are directly used without additional correction, but acoustic performance is a relatively small value measured in real numbers of two decimal places or less, so calculations are cumbersome. In the case of porous polymer materials, the deviation in acoustic performance is large due to the irregular internal porous structure, which reduces the reliability of the prediction model.

The present disclosure provides a method of predicting acoustic performance of a polymer material that deteriorates over time at a certain temperature, and a program to perform the same.

Another object of the present disclosure is to provide a method of reliably predicting acoustic performance with simple calculation and low deviation by use of corrected property values in the process of predicting acoustic performance, and a program to perform the same.

The objects of the present disclosure are not limited to the foregoing. The objects of the present disclosure will be able to be clearly understood through the following description and to be realized by the means described in the claims and combinations thereof.

An aspect of the present disclosure provides a method of predicting acoustic performance of a porous polymer material, including: measuring, by a controller, initial properties of a polymer material including non-acoustic properties and mechanical properties; calculating, by the controller, properties after deterioration by inputting the initial properties into a deterioration model; and calculating, by the controller, acoustic performance after deterioration of the polymer material by inputting the properties after deterioration into an acoustic model.

In one embodiment, the polymer material may include urethane foam.

In one embodiment, the non-acoustic properties may include at least one selected from among porosity, airflow resistivity, tortuosity, viscous characteristic length, thermal characteristic length, and static thermal permeability.

In one embodiment, the mechanical properties may include at least one selected from among Young's modulus, loss factor, and Poisson ratio.

In one embodiment, the deterioration model may be application of a Layton model and an Arrhenius model in combination.

In one embodiment, the deterioration model may be used to calculate changes in the non-acoustic properties and the mechanical properties of the polymer material depending on time (t) and temperature (T).

In one embodiment, the method may further include determining constants of the deterioration model after measuring the initial properties.

As such, determining the constants may include obtaining a plurality of test data by measuring properties of the polymer material after leaving the polymer material at a predetermined temperature T(in which i is an integer of 1 or more) for a predetermined time t(in which j is an integer of 1 or more), converting the measured properties into corrected properties using a maximum value and a minimum value among the test data, and determining constants of the deterioration model using the method of least squares based on the corrected properties.

Also, the predetermined temperature Tin determining the constants preferably includes at least three temperatures.

In one embodiment, the deterioration model may be represented by Equation 1 below.

Here, P may be the properties of a polymer material, P(t,T) may be the properties after deterioration of the polymer material deteriorated at a temperature T for a time t, αmay be the initial corrected properties, Pmay be the maximum value of the properties of the polymer material measured in determining the constants, Pmay be the minimum value of the properties of the polymer material measured in determining the constants, A may be the Arrhenius constant calculated by determining the constants, and B may be the ratio of ideal gas constant and activation energy calculated by determining the constants.

In one embodiment, the acoustic model may include calculating acoustic performance after deterioration by applying a JCAL (Johnson-Champoux-Allard-Lafarge) or Biot-JCAL model.

In one embodiment, the acoustic model may include calculating acoustic properties after deterioration of the polymer material based on the properties after deterioration, obtaining a transfer matrix using the acoustic properties after deterioration, and calculating the acoustic performance after deterioration of the polymer material using a matrix component of the transfer matrix.

As such, calculating the acoustic properties after deterioration may include calculating equivalent acoustic characteristics based on the properties after deterioration, and calculating the acoustic properties after deterioration of the polymer material using the equivalent acoustic characteristics.

In one embodiment, the acoustic performance may include sound absorption coefficient and sound transmission loss after deterioration of the polymer material.

Another aspect of the present disclosure provides a non-transitory computer readable medium containing program instructions executed by a processor, the computer readable medium including: program instructions that measure initial properties of a polymer material comprising non-acoustic properties and mechanical properties; program instructions that calculate properties after deterioration by inputting the initial properties into a deterioration model; and program instructions that calculate acoustic performance after deterioration of the polymer material by inputting the properties after deterioration into an acoustic model.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.

Further, the control logic of the present disclosure may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN).

The above and other objects, features and advantages of the present disclosure will be more clearly understood from the following preferred embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein, and may be modified into different forms. These embodiments are provided to thoroughly explain the disclosure and to sufficiently transfer the spirit of the present disclosure to those skilled in the art.

Throughout the drawings, the same reference numerals will refer to the same or like elements. For the sake of clarity of the present disclosure, the dimensions of structures are depicted as being larger than the actual sizes thereof. It will be understood that, although terms such as “first”, “second”, etc. may be used herein to describe various elements, these elements are not to be limited by these terms. These terms are only used to distinguish one element from another element. For instance, a “first” element discussed below could be termed a “second” element without departing from the scope of the present disclosure. Similarly, the “second” element could also be termed a “first” element. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms “comprise”, “include”, “have”, etc., when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. Also, it will be understood that when an element such as a layer, film, area, or sheet is referred to as being “on” another element, it may be directly on the other element, or intervening elements may be present therebetween. Similarly, when an element such as a layer, film, area, or sheet is referred to as being “under” another element, it may be directly under the other element, or intervening elements may be present therebetween.

Unless otherwise specified, all numbers, values, and/or representations that express the amounts of components, reaction conditions, polymer compositions, and mixtures used herein are to be taken as approximations including various uncertainties affecting measurement that inherently occur in obtaining these values, among others, and thus should be understood to be modified by the term “about” in all cases. Furthermore, when a numerical range is disclosed in this specification, the range is continuous, and includes all values from the minimum value of said range to the maximum value thereof, unless otherwise indicated. Moreover, when such a range pertains to integer values, all integers including the minimum value to the maximum value are included, unless otherwise indicated.

In the present specification, when a range is described for a variable, it will be understood that the variable includes all values including the end points described within the stated range. For example, the range of “5 to 10” will be understood to include any subranges, such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, and the like, as well as individual values of 5, 6, 7, 8, 9 and 10, and will also be understood to include any value between valid integers within the stated range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, and the like. Also, for example, the range of “10% to 30%” will be understood to include subranges, such as 10% to 15%, 12% to 18%, 20% to 30%, etc., as well as all integers including values of 10%, 11%, 12%, 13% and the like up to 30%, and will also be understood to include any value between valid integers within the stated range, such as 10.5%, 15.5%, 25.5%, and the like.

A method of predicting acoustic performance of a porous polymer material according to the present disclosure may include measuring initial properties of a polymer material including non-acoustic properties and mechanical properties, calculating properties after deterioration by inputting the initial properties into a deterioration model, and calculating acoustic performance after deterioration of the polymer material by inputting the properties after deterioration into an acoustic model.

Below is a detailed description of individual steps.

First, a polymer material, acoustic performance after deterioration of which is to be predicted, is selected. Here, the polymer material may include a porous polymer material, for example, polyurethane foam.

Thereafter, initial properties of the polymer material are measured. The initial properties may include non-acoustic properties and mechanical properties necessary to calculate properties and acoustic performance after deterioration using the deterioration model.

The non-acoustic properties include, for example, at least one selected from among porosity, airflow resistivity, tortuosity, viscous characteristic length, thermal characteristic length, and static thermal permeability. Also, the mechanical properties may include, for example, at least one selected from among Young's modulus, loss factor, and Poisson ratio.

Herein, definitions of individual properties included in the non-acoustic properties and mechanical properties may be understood as known in the relevant technical field, and measurement methods thereof are not particularly limited and include general measurement methods used in the relevant technical field.

After measuring the initial properties of the polymer material, properties after deterioration may be calculated by inputting the initial properties into a deterioration model. Here, the deterioration model may be used to calculate the properties that change as the polymer material deteriorates by being left at any temperature (T) for any time (t), and may be application of the Layton model and the Arrhenius model in combination.

As provided herein, the calculations may be performed by a controller. For example, the calculations performed with respect to the deterioration model may be performed by one or more units or modules of the controller that constitute hardware components that form part of a controller (e.g., modules or devices of a high-level controller), or may constitute individual controllers each having a processor and memory. The controller may include one or more processors and memory.

Also, the term “properties” may be understood as non-acoustic properties or mechanical properties, unless otherwise stated.

In one embodiment, the deterioration model may be represented by Equation 1 below.

Here, P may refer to the properties of the polymer material, and P(t,T) may refer to the properties after deterioration of the polymer material deteriorated by being left at a temperature T (° C.) for a time t (hour).

αmay refer to the initial corrected properties obtained by correcting the initial properties through determining constants to be described later.

Pmay refer to the maximum value of the properties of the polymer material measured in determining the constants to be described later, and Pmay refer to the minimum value of the properties of the polymer material measured in determining the constants to be described later.

A may refer to the Arrhenius constant calculated by determining the constants to be described later, and B may refer to the ratio of ideal gas constant and activation energy calculated by determining the constants to be described later.

In Equation 1, P, P, α, A, and B may be used as are until the type of polymer material is changed after being set by determining the constants to be described later. Thus, using the deterioration model according to the present disclosure, the properties after deterioration of the polymer material may be more easily predicted without additional experiments.

Meanwhile, if the constants of P, P, α, A, and B of Equation 1 are not determined in calculating the properties after deterioration, this step may be further performed to determine the same.

Specifically, a plurality of test data may be obtained by measuring the properties of the polymer material after leaving the polymer material at a predetermined temperature T(in which i is an integer of 1 or more) for a predetermined time t(in which j is an integer of 1 or more).